Capacitation-dependent concentration of lipid rafts in the apical ridge head area of porcine sperm cells

Lipid architecture of the plasma membrane plays an important role in the capacitation process of the sperm cell. During this process, an increase in membrane fluidity takes place, which coincides with a redistribution of cholesterol to the apical region of the head plasma membrane and subsequently an efflux of cholesterol. Cholesterol is also a major player in the formation of lipid rafts or microdomains in the membrane. Lipid rafts favour specific protein-protein interactions by concentrating certain proteins in these microdomains while excluding others. In this study, we investigated the organization of lipid rafts during in vitro capacitation of boar sperm cells. We report on the presence of the lipid raft-specific proteins caveolin-1 and flotillin-1 in sperm cells. Capacitation induced a change in membrane distribution of these proteins. Lipid analysis on detergent-resistant membranes (DRMs) of sperm cells indicated that capacitation induces a lipid raft concentration rather than a disintegration of lipid rafts, because the total amount of lipid in the DRM fraction remained unaltered. Using a proteomic approach, we identified several major DRM proteins, including proteins involved in capacitation-dependent processes and zona pellucida binding. Our data indicate that sperm raft reorganization may facilitate capacitation-specific signalling events and binding to the zona pellucida.     

健康成人血液流变学与血脂相关性的实验研究

目的：研究健康成人血液流变学指标与血脂之间的相关性。方法：抽取西安市某单位健康查体人群各项检查结果齐全的资料117例，其中男性79例，女性38例，将采集的数据进行统计分析。结果：男性和女性之间，TG、HBV、LBV、HRV、LRV、CV、CY均有显著差异（P〈0.05）；女性资料中，血脂指标与血液流变学指标的相关性无统计学意义（P〉0．05）；男性资料中，血液流变学指标与血脂指标有相关性（P〈0．05）。结论：控制血液粘度和血脂水平是防止和减低心脑血管疾病发生的重要环节。     

C57BL/6小鼠胆结石形成中固醇载体蛋白2的mRNA水平和胆固醇饱和指数增高

目的观察C57BL/6鼠胆囊结石形成过程中肝固醇载体蛋白2(SCP2)mRNA水平及胆囊胆汁中胆固醇饱和指数的变化。方法C57BL/6鼠20只,分为结石组和对照组。对照组喂普通饲料,结石组采用1%的胆固醇饮食4周;RT-PCR方法检测肝SCP2 mRNA水平的变化;全自动生化仪检测胆脂,并计算胆固醇饱和指数。结果胆囊结石组肝SCP2 mRNA水平显著升高,胆汁胆固醇饱和指数亦显著增加。结论肝SCP2的表达及胆汁CSI的增高呈正相关。     

Lp(a) lipoprotein is a major risk factor for cardiovascular disease: pathogenic mechanisms and clinical significance

The results of two previous and two recent studies of middle-aged males and females are presented to exemplify the clinical importance of lipoprotein (a) (Lp(a)) as a risk factor for atherosclerosis and coronary heart disease. In these studies various conventional and recently suggested risk factors were included and different methods for Lp(a) quantification were used. Lp(a) was a significant risk factor in all four studies. In the recent prospective case-control study, Lp(a) and cholesterol were found to act synergistically and predict primary acute myocardial infarction in Swedish males. A cholesterol level above 6.5 mmol/1 increased the risk of acute myocardial infarction if the Lp(a) level was above 200 mg/1. The plasma apo A-I level was a protective factor. In the other recent case-control study, an Lp(a) level above 500 mg/1 was a highly significant risk factor in Black and White US women with myocardial infarction or advanced coronary artery disease in addition to low density lipoprotein cholesterol levels above 130 mg/dl. A high apo A-I level was a protective factor. In these studies no other factors tested reached significance in multivariate logistic regression analysis. A hypothetical association between high Lp(a) levels and intracellular infection with Chlamydia pneumoniae is discussed. The results suggest that the Lp(a) level is useful in identifying high-risk individuals. Lowering low density lipoprotein cholesterol below 100 mg/dl (7lt;2.6 mmol/1) seems to be most important in both males and females with high-risk Lp(a) levels.     

Effect of recent alcohol intake on acceptor properties of high-density lipoproteins and their interaction with liver cells

Institute of Therapy, Siberian Branch, Academy of Medical Sciences of the USSR, Novosibirsk. All-Union Preventive Medicine Research Center, Ministry of Health of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR Yu. P. Nikitin.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 110, No. 12, pp. 611–613, December, 1990.     

Effect of sodium citrate on the rate of cholesterol esterification and on the formation of primary products of lipid peroxidation in human blood. Are these processes related?

In vitro experiments show that sodium citrate in a final concentration of 130 mM induces a 4- to 5-fold increase in the activity of lecithin-cholesterol acyltransferase. A parallel determination of the blood content of primary products of lipid peroxidation reveals a 20–30% decrease in diene and triene conjugates and lipid hydroperoxides. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 9, pp. 323–325, September, 1995 Presented by A. N. Klimov, Member of the Russian Academy of Medical Sciences     

Influence of serum paraoxonase polymorphism on serum lipids and apolipoproteins

One hundred and sixty-three healthy Chinese subjects of both sexes were studied for serum paraoxonase (PON) polymorphism, and levels of lipids and apolipoproteins in order to examine effects of PON alleles on these parameters. The level of serum triglyceride was significantly higher in high activity allele (PON*B) compared with that in low activity allele (PON*A) in both sexes (P less than 0.01). The subjects with PON A had significantly higher LDL cholesterol (P less than 0.05) and lower Apo A-II and ApoB levels. The influence of serum paraoxonase on serum lipids was estimated further by Spearman's rank correlation. In the males, there was a significant negative correlation of serum paraoxonase activity with total (P less than 0.05) and LDL (P less than 0.01) cholesterol levels, and positive correlation with HDL cholesterol and Apo A-II levels (P less than 0.05). Serum paraoxonase activity had a high positive correlation with serum triglyceride levels in both sexes (P less than 0.001). Serum ApoB level had a positive correlation with the enzyme activity only in females (P less than 0.01). The allelic effect of PON on these parameters was studied by multiple regression analysis. The high activity allele (PON*B) was associated with higher serum triglyceride level (P less than 0.001) and ApoB (P less than 0.001), while it had lowering influence on total cholesterol (P less than 0.05) and LDL cholesterol (P less than 0.005) in men. The average allelic effect of PON was found to be about 22% for serum triglycerides, 11% for LDL cholesterol, 14% for Apo A-II and 19% for Apo B in the present study. This study suggests a possible significant role of serum paraoxonase alleles in the metabolism of serum lipids and apolipoproteins.     

Effect of micronized fenofibrate (Lipanthyl-200M) on cholesterol synthesis in peripheral blood lymphocytes in hyperlipidemic patients with coronary heart disease

The rate of cholesterol synthesis in peripheral blood lymphocytes and plasma lipid and lipoprotein spectra are studied in patients with isolated hypercholesterolemia and combined hyperlipidemias (IIa and IIb hyperlipidemias according to Frederickson classification).¹⁴C-acetate incorporation into cholesterol in peripheral blood lymphocytes is considerably higher in patients with type IIb hyperlipidemia. Lipanthyl-200M reduces the rate of cholesterol synthesis in lymphocytes of both groups. A direct correlation is established between serum triglyceride level and the rate of cholesterol synthesis. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 125, No. 5, pp. 569–573, May, 1998     

慢性肾功能衰竭红细胞变形能力与红细胞膜的研究

本文报道了慢性肾功能衰竭患者红细胞的变形能力、红细胞膜胆固醇与磷脂比值及膜微粘度。结果表明,红细胞可变形能力明显降低,膜胆固醇与磷脂比值及膜微粘度明显增加,提示红细胞变形能力可能与红细胞膜的流动性有关。